1. Field of the Invention
This invention relates in general to the administration of parenteral fluids and more particularly to the administration of measured quantities of blood during simultaneous infusion of other intravenous fluids.
2. Description of the Prior Art
During surgery it is often desirable to infuse blood while at the same time administering other essential fluids. It is also desirable, and frequently critical when operating on children, that accurately measured amounts of blood be infused to replace blood lost through the surgery. Time lost through manual manipulation of valves can have disastrous consequences. One standard procedure at the present time includes the use of a Y-connector wherein one inlet is connected to a manually operated valve attached to a blood bag, the other inlet is connected to a syringe, and the outlet is connected to a needle. The valve is opened, blood withdrawn into the syringe, the valve closed, and the blood infused. Disadvantages include possible blood withdrawal from the infant and the crucial time lost in manually operating the valve. A second procedure currently in use is the employment of a 3-way stopcock, one inlet being connected to the blood bag, the other inlet to a syringe, and the outlet to the needle. Proper manipulation of the stopcock prevents blood withdrawal from the infant but has the disadvantage of manual operation and separation of connectors too frequently occurs.
Relevant prior art includes the flexible check valve of Willet, U.S. Pat. No. 2,999,499, the administration apparatus of Moore, U.S. Pat. No. 2,866,457, and the more recent apparatus of Dabney, U.S. Pat. No. 3,844,283.
The system developed by Willet permits withdrawal of fluid from container 6 by retracting plunger 30 of syringe 26 while simultaneously flexing valve 22, the fluid then being injectible through needle 19 by placing a positive pressure on the plunger. While this procedure does away with stopcocks and the accidental discoupling of connectors therefrom, it has the disadvantage of allowing possible aspiration of air or body fluids through needle 19.
The apparatus of Moore does not permit aspiration of fluid from container 6 for aseptic infusion through needle 19. Dabney discloses apparatus for infusion of measured volumes of fluid but uses manually operated valves, has no provision for simultaneous infusion of other fluids, and is not a closed system and therefore unsuitable for administration of blood.